Thanos is a fictional supervillain appearing in American comic books published by Marvel Comics. The character, created by writer/artist Jim Starlin, first appeared in The Invincible Iron Man #55 (cover dated February 1973). Thanos is one of the most powerful villains in the Marvel Universe and has clashed with many heroes including the Avengers, the Guardians of the Galaxy, the Fantastic Four, and the X-Men.
Thanos is in love with Lady Death, to the extent he would attempt to become the god of death, to kill half the universe, just to please Lady Death. He is, in all actuality, a yandere.